We modify a method recently suggested by Martin Weitzman (2012) for determining a risk-adjusted social discount rate (SDR) term structure consistent with both the (augmented) Ramsey rule and the consumption-based CAPM. Using this approach we estimate SDR for transportation infrastructure...

Tail-hedge discounting is based on decomposition of returns from long-term investments in a fraction (gamma) that is correlated with consumption and another that is not. The first part is discounted at a discount rate that includes a risk premium, the other with the risk-free rate. We estimate...

Weitzman (2012, 2013) has suggested a method for calculating social discount rates for long-term investments when project returns are covariant with consumption or other macroeconomic variables, so called "tail-hedge discounting". This method relies on a parameter called "real project gamma"...